When we saw glimpses of Sapphire Radeon HD 7970 Toxic 6 GB graphics card, we knew Sapphire was prioritizing on aesthetics a lot. That turns out to be the case, as the first pictures of this monstrosity reveal. The PCB and cooler are designed from scratch, by Sapphire. The PCB accommodates 6 GB of memory in 24 GDDR5 memory chips, 12 on each side. To power the factory-overclocked 28 nm "Tahiti" GPU and 24 GDDR5 7 GT/s memory chips takes some really strong VRM. Sapphire implemented an 8+3 phase power supply, that makes use of solid-state chokes (don't whine under stress), and International Rectifier DirectFETs. The VRM draws power from two 8-pin PCIe power connectors.

More details, and a benchmark follow.

The VRM includes, we're told, a very high-end controller that provides a lot of software features. On the card, Sapphire implemented LEDs for each of the 8 vGPU phases, that gives you a real-time indication of their individual loading. These LEDs can be seen through a window on the top of the card.

The cooler consists of a large, monolithic aluminum fin heatsink that draws heat from the GPU and memory chips on the obverse side of the PCB. The FETs on the obverse side are cooled by additional heatsinks. The memory chips on the reverse side of the PCB are cooled by a fancy-looking metal back-plate. The heatsink makes use of four 8 mm-thick nickel-plated copper heat pipes, as well as a vapor-chamber plate. It is ventilated by two 80 mm fans.

The card features out of the box clock speeds of 1150 MHz (core), and 1500 MHz (6.00 GHz GDDR5 effective) memory. It includes dual-BIOS, with a failsafe BIOS. OCLab managed to overclock the card with its included cooler, to 1300 MHz (core) and 1900 MHz (memory), and put the contraption through 3DMark 11. It scored P12463 points in performance preset. Other details of the test-bed are in the screenshot below.

So... i guess the waiting is over.
All we need now is some cherry-picked GPUs to form the fastest graphics card on the planet AKA ATOMIC.
Benefit of 6GB of VRAM is mainly marketing, Secondly running monster resolutions (7680X1600 for example) and even then you gotta flex your game modding skills to squeeze some extra rendering

Not true. It's already overloaded with memory bandwidth if compared to the GTX 680.

You need atleast 7680*3200 Resolution monitor to completely use it considering the fact the 2 GB on the 5870 Eyefinity6 was enough to run 6 full HD monitors.
6 GB is very useful if you are crossfiring a pair of these.